<template>
  <div class="flow-menu" ref="tool">
    <div v-for="menu in menuList" :key="menu.id">
      <div class="ef-node-pmenu-item"><i class="el-icon-notebook-2"></i>节点配置</div>
      <ul v-show="menu.open" class="ef-node-menu-ul">
        <draggable
          @end="end"
          @start="move"
          v-model="menu.children"
          :options="draggableOptions"
        >
          <li
            v-for="subMenu in menu.children"
            class="ef-node-menu-li"
            :key="subMenu.id"
            :type="subMenu.type"
          >
            <i :class="subMenu.ico"></i> {{ subMenu.name }}
          </li>
        </draggable>
      </ul>
    </div>
  </div>
</template>
<script>
import { VueDraggableNext as draggable } from "vue-draggable-next";

var mousePosition = {
  left: -1,
  top: -1,
};

export default {
  data() {
    return {
      activeNames: "1",
      // draggable配置参数参考 https://www.cnblogs.com/weixin186/p/10108679.html
      draggableOptions: {
        preventOnFilter: false,
        sort: false,
        disabled: false,
        ghostClass: "tt",
        // 不使用H5原生的配置
        forceFallback: true,
        // 拖拽的时候样式
        // fallbackClass: 'flow-node-draggable'
      },
      // 默认打开的左侧菜单的id
      defaultOpeneds: ["1", "2"],
      originNodes: [],
      menuList: [
        {
          id: "1",
          type: "group",
          name: "开始节点",
          ico: "el-icon-video-play",
          open: true,
          children: [
            {
              id: "0",
              type: "start",
              name: "流程开始",
              ico: "el-icon-time",
              // 自定义覆盖样式
              style: {},
            },
            {
              id: "1",
              type: "end",
              name: "流程结束",
              ico: "el-icon-switch-button",
              // 自定义覆盖样式
              style: {},
            },
            {
              id: "2",
              type: "cc",
              name: "流程抄送",
              ico: "el-icon-s-promotion",
              // 自定义覆盖样式
              style: {},
            },
            {
              id: "3",
              type: "node",
              name: "流程节点",
              ico: "el-icon-news",
              // 自定义覆盖样式
              style: {},
            },
          ],
        },
      ],

      nodeMenu: {},
    };
  },
  components: {
    draggable,
  },
  created() {
    this.originNodes = [...this.menuList[0].children];
    /**
     * 以下是为了解决在火狐浏览器上推拽时弹出tab页到搜索问题
     * @param event
     */
    if (this.isFirefox()) {
      document.body.ondrop = function (event) {
        // 解决火狐浏览器无法获取鼠标拖拽结束的坐标问题
        mousePosition.left = event.layerX;
        mousePosition.top = event.clientY - 50;
        event.preventDefault();
        event.stopPropagation();
      };
    }
  },
  methods: {
    // 根据类型获取左侧菜单对象
    getMenuByType(type) {
      for (let i = 0; i < this.menuList.length; i++) {
        let children = this.menuList[i].children;
        for (let j = 0; j < children.length; j++) {
          if (children[j].type === type) {
            return children[j];
          }
        }
      }
    },
    // 拖拽开始时触发
    move(evt, a, b, c) {
      var type = evt.item.attributes.type.nodeValue;
      this.nodeMenu = this.getMenuByType(type);
    },
    // 拖拽结束时触发
    end(evt, e) {
      this.$emit("addNode", evt, this.nodeMenu, mousePosition);
      this.menuList[0].children = [...this.originNodes];
    },
    // 是否是火狐浏览器
    isFirefox() {
      var userAgent = navigator.userAgent;
      if (userAgent.indexOf("Firefox") > -1) {
        return true;
      }
      return false;
    },
  },
};
</script>
<style scoped lang="less">
@import "./index.css";
</style>
